1. Technical Field
The present disclosure generally relates to printed circuit boards (PCBs), and particularly, relates to a method for making a multilayer printed circuit board, and a multilayer printed circuit board made by the method.
2. Description of Related Art
To accommodate the development of miniaturized electronic products with multiple functions, multilayer printed circuit boards are widely used due to their characteristics such as lightness and high-density inter-connectability.
Multilayer printed circuit boards are manufactured using a typical sheet-by-sheet process. Firstly, a core substrate is provided, and an inner electrically conductive trace is formed on the core substrate. Secondly, an adhesive layer and a first electrically conductive layer such as copper foil are laminated onto the core substrate. Thirdly, an electrically conductive trace is formed in the first electrically conductive layer. Afterwards, another adhesive layer and a second electrically conductive layer are laminated onto the electrically conductive trace of the first electrically conductive layer, and another electrically conductive trace is formed in the second electrically conductive layer, thus a multilayer printed circuit board is obtained. However, only one electrically conductive layer can be laminated together at a time. During the processes of laminating the first and second electrically conductive layers and forming electrically conductive traces, conditions such as environmental factors may vary, so different degrees of shrinkage and expansion among the layers make it difficult to align the layers.
What is needed, therefore, is a method for manufacturing a multilayer printed circuit board and a multilayer printed circuit board to overcome the above-described problems.